where are the media of nostr stored? do users run nodes of nostr by storing all messages and media on their own hard drives?

The media are usually hosted on external sites i.e. nostr.build or satellite.earth Or some clients like Primal offer their own media hosting within the client I think by default nostr relays only contain text, but there are technologies being worked on like Blossom which, as I understand, is basically like nostr relays but for (encrypted) media. PS I'm not very technical so I might off here somewhere 🙃 If I'm wrong anywhere then hopefully some more code-literate persons such as @fiatjaf, @hzrd149, @miljan, @Vitor Pamplona or @The Fishcake (nostr.build) can correct me :)

You got everything right except the encrypted part. The files stored on blossom servers is not encrypted

Clients (like ours) can and do encrypt content before pushing to blossom though